From the Guidelines
Alkali burns are worse than acid burns in the eye because they penetrate deeper, cause more extensive damage, and disrupt the eye's pH balance more severely, leading to continued tissue destruction and a higher risk of complications. When an alkali chemical contacts the eye, it rapidly breaks down cell membranes and proteins through a process called saponification, allowing it to continue penetrating through the cornea and into deeper eye structures 1. Unlike acids, which typically cause immediate coagulation of proteins that creates a barrier limiting further penetration, alkali substances continue to damage tissues progressively over time. The key to first aid in such cases is rapid removal of the caustic agent, and running water is a readily available resource that has been demonstrated to be an effective decontamination agent 1. Additionally, alkali burns disrupt the eye's pH balance more severely and for longer periods, leading to continued tissue destruction even after the initial exposure. The liquefactive necrosis caused by alkali burns results in more profound structural damage to the cornea, conjunctiva, and potentially the lens and retina, often leading to more severe scarring, vision loss, and a higher risk of complications like glaucoma and cataracts. Some studies have shown that immediate irrigation can reduce the number of full-thickness burns, mean hospital days, and delayed complications 1. Therefore, alkali burns require more aggressive and immediate treatment, including copious irrigation to normalize the pH and often more intensive medical intervention. It is essential to prioritize the preservation of vision and seek immediate evaluation by a healthcare professional, as recommended by the American Heart Association and American Red Cross guidelines for first aid 1. In case of exposure to an alkali on the skin or eye, immediately irrigate the affected area with copious amounts of water, and remove all contaminated clothing from the victim, making sure not to contaminate yourself in the process 1.
From the Research
Comparison of Alkaline and Acid Burns
- Alkaline burns are considered more severe than acid burns due to their ability to rapidly penetrate the cornea and anterior chamber, causing disruption of cells and tissue softening 2.
- The high pathological potential of alkaline burns is attributed to their ability to lyse cell membranes and penetrate intraocular structures, resulting in devastating outcomes 3.
- Acid burns, on the other hand, tend to cause more superficial damage to the ocular surface, although they can still lead to significant visual impairment if not properly managed.
Mechanism of Injury
- Alkali burns combine with cell membrane lipids, resulting in disruption of cells and stromal mucopolysaccharides, and concomitant tissue softening 2.
- This rapid penetration and disruption of tissue can lead to more severe and long-lasting damage compared to acid burns.
- The extent of the damage depends on the severity of the burn, the type of chemical involved, and the promptness and effectiveness of treatment.
Clinical Implications
- Effective emergency measures, including copious irrigation and topical antibiotics, are crucial in minimizing the damage caused by alkaline burns 3, 4.
- Early aggressive intervention and rigorous follow-up can improve visual outcomes and reduce the risk of complications such as cicatrical ectropion, pseudoexfoliative syndrome, and symblepharon 3.
- The management of chemical burns requires a multidisciplinary approach, involving cooperation between ophthalmic staff and burns units, to ensure optimal care and rehabilitation of patients 3, 4.